linux-kernel - Re:[PATCH 1/5] drm/rockchip: vop2: Add high color depth support

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Message-ID: <3ceb2c70.2145.1982ff28b9c.Coremail.andyshrk@163.com>
Date: Tue, 22 Jul 2025 10:24:41 +0800 (CST)
From: "Andy Yan" <andyshrk@....com>
To: "Cristian Ciocaltea" <cristian.ciocaltea@...labora.com>,
	"Algea Cao" <algea.cao@...k-chips.com>
Cc: "Sandy Huang" <hjc@...k-chips.com>,
	Heiko Stübner <heiko@...ech.de>,
	"Andy Yan" <andy.yan@...k-chips.com>,
	"Maarten Lankhorst" <maarten.lankhorst@...ux.intel.com>,
	"Maxime Ripard" <mripard@...nel.org>,
	"Thomas Zimmermann" <tzimmermann@...e.de>,
	"David Airlie" <airlied@...il.com>,
	"Simona Vetter" <simona@...ll.ch>,
	"Andrzej Hajda" <andrzej.hajda@...el.com>,
	"Neil Armstrong" <neil.armstrong@...aro.org>,
	"Robert Foss" <rfoss@...nel.org>,
	"Laurent Pinchart" <Laurent.pinchart@...asonboard.com>,
	"Jonas Karlman" <jonas@...boo.se>,
	"Jernej Skrabec" <jernej.skrabec@...il.com>, kernel@...labora.com,
	dri-devel@...ts.freedesktop.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re:[PATCH 1/5] drm/rockchip: vop2: Add high color depth support


Hello Cristian，

At 2025-07-22 01:39:04, "Cristian Ciocaltea" <cristian.ciocaltea@...labora.com> wrote:
>Take the bits per color channel into consideration when computing DCLK
>rate.
>
>Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>
>---
> drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 3 +++
> 1 file changed, 3 insertions(+)
>
>diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>index 186f6452a7d359f079662bc580850929632ea8fe..a714bcbb02de16267e7febbaeb1eb270c70aaef2 100644
>--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>@@ -1731,6 +1731,9 @@ static void vop2_crtc_atomic_enable(struct drm_crtc *crtc,
> 		clock *= 2;
> 	}
> 
>+	if (vcstate->output_bpc > 8)
>+		clock = DIV_ROUND_CLOSEST(clock * vcstate->output_bpc, 8);


This seems not right,  regardless of the value of bpc, the dclk of VOP must be
consistent with mode->crtc_clock.
If the dclk of VOP is increased in accordance with the BPC ratio here, then the refresh rate of VOP will also increase proportionally.
This would be inconsistent with the timing described in the mode.
For a hight color depth,  the frequency needs to be increased for the HDMI PHY's clock.


>+
> 	vop2_vp_write(vp, RK3568_VP_MIPI_CTRL, 0);
> 
> 	/*
>
>-- 
>2.50.0